1. Field
The present disclosure relates to single-stranded nucleic acid aptamers specifically binding to Escherichia coli (E. coli) and methods for detecting E. coli using the same.
2. Description of the Related Art
To identify existence of harmful microorganisms in a water system, current practice involves detection of total coliforms present in the water, indicated by an index number. With regards to drinking water, existence of coliforms is measured based on the ability of degrading lactose. However, experimental methods of measuring the existence of coliforms are very complicated to require long experimental turnaround time (over 4 days), and also has high error rate and inaccuracy since the results are calculated based on statistical table. Therefore, a highly accurate E. coli monitoring sensor system for real-time monitoring of microorganism contamination of a water system due to pathogenic microorganism existence is required. In particular, securing of a receptor that recognizes E. coli with high specificity is essential for development of a highly sensitive and stable E. coli monitoring system.
Aptamer is a single-stranded nucleic acid with high specificity and affinity for various target substances. The related art sensor technologies for diagnosing diseases or for detecting harmful microorganisms mostly rely on immunological analysis using antibodies. Recent studies have been relying upon biosensor technology, wherein aptamers of high specificity and affinity for target substances are used in diagnosing diseases. Various chemical functional groups may be given to terminals of aptamers, and the specificity and affinity of aptamers may be maximized during a procedure of being selected in vitro. An aptamer may be mass-produced with high-purity and low-cost through chemical synthesis, and may be stored under room temperature for extended periods, as aptamers are thermally stable. In addition, aptamers may be enhanced with respect to their specificity for target substances by performing a counter selection on various materials which have a similar structure with the target or are largely present in actual samples.
Therefore, the present disclosure provides a simple, quick and accurate method of detecting the presence of E. coli within a water system by incorporating single-stranded nucleic acid aptamers specifically binding to E. coli. 